A study was conducted to see if the herbal supplement helped to reduce weight. After 12 weeks, 42 subjects using herbal supplement and a high-fiber, low-calorie diet had mean weight loss of 3.2 kg. And standard deviation of 3.3 kg. Throughout the same period, 42 subjects using a placebo and the high-fiber, low-calorie diet had mean weight loss of 4.1 kg. And standard deviation of 3.9 kg.
At a = .05, test the claim that the mean weight loss for group using the herbal supplement is greater than the mean weight loss for group using the placebo.